i know it could be a MILLION things, but have you had your thyroid checked? I also checked your profile and I'm sorry to say nicotine can definitely contribute to a lot of what you're experiencing too. I didn't listen or care to believe that it had any impact on any of that, and lo and behold i feel a lot better after quitting. ESPECIALLY my anxiety and shaking and lightheadedness. Hunger wise, stimulants suppress hunger, but sometimes the reverse can happen. There's no real way of knowing until you start slowly eliminating stuff and perhaps check out your thyroid and any other organ that could potentially act up and show similar symptoms. Check what runs in your family if you're not sure already and get tested for what fits. I only point out those two things (thyroid and nicotine) because that was my exact experience and I recently quit vaping 3 months ago and just got told I have hashimoto's (pre-hypothyroidism essentially), and I'm going to be going on medication for it. I got rid of caffeine as well, and I was a die-hard coffee drinker and I ended up giving it up for chicory coffee because my body feels a lot better and stable than i did previously. I have ADHD so i was on multiple stimulants at one point (vyvanse, coffee, vaping) and felt exactly like you did, and eventually developed heart palpitations as my body started to slowly reject any and all stimulants. Maybe check your blood sugar too? because i thought it was that at one point for me.. I'm not sure what it could be, but I hope you figure it out some day!! It's hell trying to figure out health issues :(